Re: [PATCH v2 2/3] scsi: ufs: qcom: Map devfreq OPP freq to UniPro Core Clock freq

[Ziqi Chen]

On 5/7/2025 7:59 PM, neil.armstrong@xxxxxxxxxx wrote:
> On 07/05/2025 11:09, Ziqi Chen wrote:
> > Hi Luca,
> >
> > On 5/7/2025 4:19 PM, Luca Weiss wrote:
> > > Hi Ziqi,
> > >
> > > On Wed May 7, 2025 at 9:44 AM CEST, Ziqi Chen wrote:
> > > > From: Can Guo <quic_cang@xxxxxxxxxxx>
> > > >
> > > > On some platforms, the devfreq OPP freq may be different than the 
> > > > unipro
> > > > core clock freq. Implement ufs_qcom_opp_freq_to_clk_freq() and use 
> > > > it to
> > > > find the unipro core clk freq.
> > > >
> > > > Signed-off-by: Can Guo <quic_cang@xxxxxxxxxxx>
> > > > Co-developed-by: Ziqi Chen <quic_ziqichen@xxxxxxxxxxx>
> > > > Signed-off-by: Ziqi Chen <quic_ziqichen@xxxxxxxxxxx>
> > > > ---
> > > >   drivers/ufs/host/ufs-qcom.c | 81 +++++++++++++++++++++++++++++++ 
> > > > +-----
> > > >   1 file changed, 71 insertions(+), 10 deletions(-)
> > > >
> > > > diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
> > > > index 7f10926100a5..804c8ccd8d03 100644
> > > > --- a/drivers/ufs/host/ufs-qcom.c
> > > > +++ b/drivers/ufs/host/ufs-qcom.c
> > > > +static unsigned long ufs_qcom_opp_freq_to_clk_freq(struct ufs_hba 
> > > > *hba,
> > > > +                                                   unsigned long 
> > > > freq, char *name)
> > > > +{
> > > > +    struct ufs_clk_info *clki;
> > > > +    struct dev_pm_opp *opp;
> > > > +    unsigned long clk_freq;
> > > > +    int idx = 0;
> > > > +    bool found = false;
> > > > +
> > > > +    opp = dev_pm_opp_find_freq_exact_indexed(hba->dev, freq, 0, true);
> > > > +    if (IS_ERR(opp)) {
> > > > +        dev_err(hba->dev, "Failed to find OPP for exact frequency 
> > > > %lu\n", freq);
> > >
> > > I'm hitting this print on bootup:
> > >
> > > [    0.512515] ufshcd-qcom 1d84000.ufshc: Failed to find OPP for 
> > > exact frequency 18446744073709551615
> > > [    0.512571] ufshcd-qcom 1d84000.ufshc: Failed to find OPP for 
> > > exact frequency 18446744073709551615
> > >
> > > Doesn't look like it's intended? The number is (2^64 - 1)
> > Yes, this is expected. During link startup, the frequency
> > ULONG_MAX will be passed to ufs_qcom_set_core_clk_ctrl() and
> > ufs_qcom_cfg_timer(). This frequency cannot be found through the API
> > dev_pm_opp_find_freq_exact_indexed(). Therefore, we handle the
> > frequency ULONG_MAX separately within Ufs_qcom_set_core_clk_ctrl()
> > and ufs_qcom_cfg_timer().
> >
> > This print only be print twice during link startup. If you think print
> > such print during bootup is not make sense, I can improve the code and
> > update a new vwesion.
>
> I think just don't call ufs_qcom_opp_freq_to_clk_freq() if freq==ULONG_MAX
Thanks Neil,  yes, it is a way , let me discuss internally and update 
new version.

BRs,
Ziqi

> Neil
>
> > BRs.
> > Ziqi
> >
> > > Regards
> > > Luca